Synopsis

Low: nss_ldap security and bug fix update

Type/Severity

Security Advisory: Low

Topic

An updated nss_ldap package that fixes a security issue and several bugs is
now available.

This update has been rated as having low security impact by the Red Hat
Security Response Team.

Description

The nss_ldap package contains the nss_ldap and pam_ldap modules. The
nss_ldap module is a plug-in which allows applications to retrieve
information about users and groups from a directory server. The pam_ldap
module allows PAM-aware applications to use a directory server to verify
user passwords.

A race condition was discovered in nss_ldap which affected certain
applications which make LDAP connections, such as Dovecot. This could cause
nss_ldap to answer a request for information about one user with
information about a different user. (CVE-2007-5794)

In addition, these updated packages fix the following bugs:

• a build error prevented the nss_ldap module from being able to use DNS to
  discover the location of a directory server. For example, when the
  /etc/nsswitch.conf configuration file was configured to use "ldap", but no
  "host" or "uri" option was configured in the /etc/ldap.conf configuration
  file, no directory server was contacted, and no results were returned.
  
• the "port" option in the /etc/ldap.conf configuration file on client
  machines was ignored. For example, if a directory server which you were
  attempting to use was listening on a non-default port (i.e. not ports 389
  or 636), it was only possible to use that directory server by including the
  port number in the "uri" option. In this updated package, the "port" option
  works as expected.
  
• pam_ldap failed to change an expired password if it had to follow a
  referral to do so, which could occur, for example, when using a slave
  directory server in a replicated environment. An error such as the
  following occurred after entering a new password: "LDAP password
  information update failed: Can't contact LDAP server Insufficient 'write'
  privilege to the 'userPassword' attribute"
  

This has been resolved in this updated package.

• when the "pam_password exop_send_old" password-change method was
  configured in the /etc/ldap.conf configuration file, a logic error in the
  pam_ldap module caused client machines to attempt to change a user's
  password twice. First, the pam_ldap module attempted to change the password
  using the "exop" request, and then again using an LDAP modify request.
  
• on Red Hat Enterprise Linux 5.1, rebuilding nss_ldap-253-5.el5 when the
  krb5-*-1.6.1-17.el5 packages were installed failed due to an error such as
  the following:
  

+ /builddir/build/SOURCES/dlopen.sh ./nss_ldap-253/nss_ldap.so
dlopen() of "././nss_ldap-253/nss_ldap.so" failed:
./././nss_ldap-253/nss_ldap.so: undefined symbol: request_key
error: Bad exit status from /var/tmp/rpm-tmp.62652 (%build)

The missing libraries have been added, which resolves this issue.

When recursively enumerating the set of members in a given group, the
module would allocate insufficient space for storing the set of member
names if the group itself contained other groups, thus corrupting the heap.
This update includes a backported fix for this bug.

Users of nss_ldap should upgrade to these updated packages, which contain
backported patches to correct this issue and fix these bugs.

Solution

Before applying this update, make sure that all previously-released
errata relevant to your system have been applied.

This update is available via Red Hat Network. Details on how to use
the Red Hat Network to apply this update are available at
http://kbase.redhat.com/faq/FAQ_58_10188

Affected Products

• Red Hat Enterprise Linux Server 5 x86_64
• Red Hat Enterprise Linux Server 5 ia64
• Red Hat Enterprise Linux Server 5 i386
• Red Hat Enterprise Linux Workstation 5 x86_64
• Red Hat Enterprise Linux Workstation 5 i386
• Red Hat Enterprise Linux Desktop 5 x86_64
• Red Hat Enterprise Linux Desktop 5 i386
• Red Hat Enterprise Linux for IBM z Systems 5 s390x
• Red Hat Enterprise Linux for Power, big endian 5 ppc
• Red Hat Enterprise Linux Server from RHUI 5 x86_64
• Red Hat Enterprise Linux Server from RHUI 5 i386

Fixes

• BZ - 254172 - Automatic DNS discovery of the LDAP server does not work
• BZ - 364501 - pam_ldap tries to change passwords twice
• BZ - 367461 - CVE-2007-5794 nss_ldap randomly replying with wrong user's data
• BZ - 427370 - RHEL 5.1 nss_ldap does not build with RHEL 5.1 krb5 packages

CVEs

• CVE-2007-5794

References

• http://www.redhat.com/security/updates/classification/#low

Red Hat Enterprise Linux Server 5

SRPM
nss_ldap-253-12.el5.src.rpm	SHA-256: 2230531a27e4853afb9351a26e87e03acd8303d30f1e81485dfb018a6220d3b9
x86_64
nss_ldap-253-12.el5.i386.rpm	SHA-256: e989eb0b3a747984b2da62d5455b7b89c3a4340853b71ee74c95af96a597cfe4
nss_ldap-253-12.el5.x86_64.rpm	SHA-256: a470b0ca30b6b281ee409eb188fb8fba704d6d9dc6a08bc3421029ceb85d41df
ia64
nss_ldap-253-12.el5.i386.rpm	SHA-256: e989eb0b3a747984b2da62d5455b7b89c3a4340853b71ee74c95af96a597cfe4
nss_ldap-253-12.el5.ia64.rpm	SHA-256: 8d28e16a9f1f6519a82ac16494e64f7a533270732314078d208443e56a91ab25
i386
nss_ldap-253-12.el5.i386.rpm	SHA-256: e989eb0b3a747984b2da62d5455b7b89c3a4340853b71ee74c95af96a597cfe4

Red Hat Enterprise Linux Workstation 5

SRPM
nss_ldap-253-12.el5.src.rpm	SHA-256: 2230531a27e4853afb9351a26e87e03acd8303d30f1e81485dfb018a6220d3b9
x86_64
nss_ldap-253-12.el5.i386.rpm	SHA-256: e989eb0b3a747984b2da62d5455b7b89c3a4340853b71ee74c95af96a597cfe4
nss_ldap-253-12.el5.x86_64.rpm	SHA-256: a470b0ca30b6b281ee409eb188fb8fba704d6d9dc6a08bc3421029ceb85d41df
i386
nss_ldap-253-12.el5.i386.rpm	SHA-256: e989eb0b3a747984b2da62d5455b7b89c3a4340853b71ee74c95af96a597cfe4

Red Hat Enterprise Linux Desktop 5

SRPM
nss_ldap-253-12.el5.src.rpm	SHA-256: 2230531a27e4853afb9351a26e87e03acd8303d30f1e81485dfb018a6220d3b9
x86_64
nss_ldap-253-12.el5.i386.rpm	SHA-256: e989eb0b3a747984b2da62d5455b7b89c3a4340853b71ee74c95af96a597cfe4
nss_ldap-253-12.el5.x86_64.rpm	SHA-256: a470b0ca30b6b281ee409eb188fb8fba704d6d9dc6a08bc3421029ceb85d41df
i386
nss_ldap-253-12.el5.i386.rpm	SHA-256: e989eb0b3a747984b2da62d5455b7b89c3a4340853b71ee74c95af96a597cfe4

Red Hat Enterprise Linux for IBM z Systems 5

SRPM
nss_ldap-253-12.el5.src.rpm	SHA-256: 2230531a27e4853afb9351a26e87e03acd8303d30f1e81485dfb018a6220d3b9
s390x
nss_ldap-253-12.el5.s390.rpm	SHA-256: a939007bd54674d975738c6de95766291b0eb30f73e81ab004e97efbcda09c01
nss_ldap-253-12.el5.s390x.rpm	SHA-256: 4a7123764a75d5d6fbe736bcac6e416810672cdbcfa1e8f857da372451e34c93

Red Hat Enterprise Linux for Power, big endian 5

SRPM
nss_ldap-253-12.el5.src.rpm	SHA-256: 2230531a27e4853afb9351a26e87e03acd8303d30f1e81485dfb018a6220d3b9
ppc
nss_ldap-253-12.el5.ppc.rpm	SHA-256: c5c7e67c4579cef4ac0526bdb253ba71085f046773635a7e5e72c33417f8de7d
nss_ldap-253-12.el5.ppc64.rpm	SHA-256: 280753fbff3ca5d05f00e183add3bf98ad01b7945bdd84ffffe465639e2219d6

Red Hat Enterprise Linux Server from RHUI 5

SRPM
nss_ldap-253-12.el5.src.rpm	SHA-256: 2230531a27e4853afb9351a26e87e03acd8303d30f1e81485dfb018a6220d3b9
x86_64
nss_ldap-253-12.el5.i386.rpm	SHA-256: e989eb0b3a747984b2da62d5455b7b89c3a4340853b71ee74c95af96a597cfe4
nss_ldap-253-12.el5.x86_64.rpm	SHA-256: a470b0ca30b6b281ee409eb188fb8fba704d6d9dc6a08bc3421029ceb85d41df
i386
nss_ldap-253-12.el5.i386.rpm	SHA-256: e989eb0b3a747984b2da62d5455b7b89c3a4340853b71ee74c95af96a597cfe4